This chapter addresses the ways that the war on terror is not simply one that targets so-called terrorist acts, but the feelings of terror generated by a range of contemporary social and political insecurities, including, but certainly not limited to, terrorist attacks such as those of September 2001. As this and other chapters in this volume suggest, fear and insecurity and powerful emotions through which the state has sought to govern domestically and internationally, thus linking political geographies of fear at the national and global scale. At the same time, these very same fears have helped to cordon off the US state by justifying the entrenchment of immigration and border policies, and the exclusionary practices surrounding them, as anxieties over population have been heightened. But moreover, feelings of terror have not only been mobilised by the US state to entrench more severe border practices, but it is through terror that the US state has sought to govern. This chapter thus takes emotion seriously, not simply as the feeling or experience of individuals or groups, but as an instrument of governance. As Sara Ahmed suggests, we need to address the politics of emotions for it is largely 'through emotions, or how we respond to objects and others, that surfaces or boundaries are made' (Ahmed 2004, 10). As Ahmed forcefully insists, this kind of analysis reveals that emotions are not simply personal or private, but are political and cultural practices that are constituted by and constitutive of social relations. As Divya Tolia-Kelly suggests, thc emotional realm is not one of universals, but rather inflected with 'visual and social registers' such as race, which denote histories and trajectories of difference and power (Tolia-Kelly 2006, 215).